Sinker cap with access slot

ABSTRACT

A radially elongated access slot extends vertically through an otherwise conventional sinker cap to permit easy withdrawal and replacement of damaged sinkers positioned under the slot without disassembly of machine elements. A retainer plate, resiliently urged in a centripetal direction and slidably attached to the underside of the sinker cap, extends into the area beneath the access slot and provides a stop means limiting centrifugal movement of sinkers and thus prevents inadvertent removal or displacement of sinkers during operation of the machine.

United States Patent 1191 Bianchi et al.

1451 Aug. 13, 1974 SINKER CAP WITH ACCESS SLOT [75] Inventors: Massimo Bianchi; Gianni Conti,

both of Firenze, Italy [73] Assignee: Billi S.p.A., Firenze, Italy [22] Filed: Aug. 8, 1972 211 App]. No; 278,726

[52] U.S. Cl. 66/107 [51] Int. Cl D04b 15/06 [58] Field of Search 66/104, 107, 108 R, 109,

[56] References Cited UNITED STATES PATENTS 1,467,691 9/1923 Scott 66/108R 2,145,986 2/1939 Lawsonetal 66/108R FOREIGN PATENTS OR APPLICATIONS l0,579 2/1909 Great Britain 66/l08 R 436,013 12/1922 Germany ..66/l08R Primary Examiner-W. C. Reynolds Assistant Examiner-A. M. Falik [57 ABSTRACT A radially elongated access slot extends vertically through an otherwise conventional sinker cap to permit easy withdrawal and replacement of damaged sinkers positioned under the slot without disassembly of machine elements. A retainer plate, resiliently urged in a centripetal direction and slidably attached to the underside of the sinker cap, extends into the area beneath the access slot and provides a stop means limiting centrifugal movement of sinkers and thus prevents inadvertent removal or displacement of sinkers during operation of the machine.

2 Claims, 4 Drawing Figures SINKER CAP WITI-I' ACCESS SLOT BACKGROUND OF THE INVENTION The invention relates to circular hosiery knitting machines of the type having radially movable sinkers which cooperate with the needles of the machine in the formation of stitches. In general, sinkers are radially guided in slots provided therefor in an annular member, called the sinker ring, attached to the upper section of the needle cylinder in the needle working zone. Sinkers are normally biased in a centripetal direction by an annular spring surrounding the outer end of the sinkers, and are adapted to be urged in a centrifugal direction by a cam track mounted in a sinker cap thus overcoming the centripetal spring bias at prescribed points to cooperate with the needles during stitch formation.

SUMMARY OF THE INVENTION The object of the present invention is to provide an improved sinker cap for such machines which permits easy withdrawal and replacement of sinkers without disassembly of machine components, which in conventional machines is frequently necessary.

According to the invention the sinker cap which carries the cam track is provided with a radially elongated access slot extending through the thickness of the sinker cap from the inner periphery thereof radially outward for a distance sufficient to permit withdrawal of a damaged sinker. By manipulating the sinkers radially against the action of the annular spring, which normally biases the sinkers centripetally, the inner end of the sinkers may be released from a seat in the needle cylinder and then inclined to facilitate withdrawal thereof through the access slot.

Additionally, a retainer plate is slidably attached to the underneath side of the sinker cap and is normally biased inwardly toward the center or centripetally into the open area beneath the access slot. So arranged the retainer plate provides a stop surface in the path of a sinker butt should the annular spring break down, so that the sinker would be prevented from moving centrifugally or radially outward which might result in inadvertent removal or displacement of the sinker. When it is desired to remove a sinker, the spring bias exerted against the retainer plate is easily overcome by an external force (manually) to facilitate withdrawal of the sinker.

The invention will be better understood following a reading of the specification in light of the accompanying drawings, which illustrate one embodiment of the invention, although not restricted thereto. In the drawings:

FIG. 1 is a partial plan view of an annular sinker cap constructed in accordance with the present invention;

FIG. 2 is a sectional view taken substantially along line 11-11 of FIG. I and further illustrating a conventional needle cylinder and associated components under normal operating conditions;

FIG. 3 is a sectional view similar to FIG. 2 but illustrates the sinker moved to a position for withdrawal; and

FIG. 4 is a sectional view taken substantially along line IV-IV of FIGS. 1 and 2.

Turning now to the accompanying drawings, the present invention is adapted for use on conventional knitting machines which include a needle cylinder 1 to which are coupled an outer sinker ring 3 and an inner ring 5 at the upper end thereof adjacent the working zone of needles 7. The rings 3 and 5 are provided with slots or seats for guiding the radial movement of the sinkers 9. The sinkers themselves include an inner extension 9A which is received in a groove 5A of the inner ring 5. An annular spring 11 surrounds the sinker ring 3 and engages the outer end of all the sinkers normally urging the sinkers in a centripetal direction. Each sinker includes at least one butt 9B which is conventionally operated by a control cam profile or track 13A borne by annular sinker cap 13 which surrounds the needle cylinder immediately above outer sinker ring 3. Under conditions of relative rotational movement between the cam track and the sinkers, the cam track 13A engages sinker butts 9B and thus urges the sinkers 9 back and forth in a radial path. The aforementioned relative, rotational movement is conventionally achieved in one of two well-known types of machines, i.e., either the needle cylinder and sinker ring rotate with respect to the sinker cap or the sinker cap is rotated with respect to the needle cylinder and sinker ring. The present invention is described in relation with the former type, however the invention is adaptable to either type machine. As is also well known, the sinkers are operated radially in cooperation with each yarn feed and thus aid in the formation of each stitch. The arrangement described hereinabove is conventional and only for the purpose of setting forth the environment of the invention, which has for its purpose the provision of a simple means for withdrawing and/or replacing sinkers.

According to the invention, the sinker cap 13 includes an access slot 15 extending vertically therethrough and horizontally elongated in a radial direction from one end of the slot in communication with the inner periphery of cap 13 toward the outer periphery of the cap a distance sufficient to permit withdrawal of a sinker therethrough as further described hereinafter. At the point of intersection of slot IS with the cam track 13A, the cam track terminates on either side of the slot to provide unimpeded access to the sinker or sinkers thereunder.

Astop means in the form of a retainer plate 17, is slidably attached to the under surface of sinker cap 13 by means of a screw 19 which extends through a radial slot 17A in plate 17. A wire spring 21 partially surrounds screw 19 and is attached at either end to one of pins 23, which extend downwardly from plate 17. The plate is thus urged radially inwards to a position against stop pins 25 attached to sinker cap 13 and which limit the inward movement of plate 17. From this position (shown in FIG. 1) plate 17 may be centrifugally urged against the resilient bias of the spring 21 when a sinker is desired to be removed. The plate 17 is normally located in a position where its inner edge 17B projects under the access opening 15 and provides a stop for the butts 98 if and when sinkers l7 undergo inadvertent centrifugal movement as a result of a breakdown of spring 11.

Under usual operating conditions (FIG. 2), the sinkers slide in the sinker ring 3 and in the inner ring 5, being guided by extensions 9A and as a result of the centrifugal effect of cams 13A and the centripetal effect of spring 11. Also in the case of breakdown of the spring 1 l, the centrifugal stroke of the sinkers is limited by the engagement of butts 98 with the inner edge 17B, while the extensions 9A remain engaged in the groove A. When one desires to withdraw a sinker through slot 15, the sinker positioned therebeneath is moved in the centrifugral direction, that is in the direction of the arrow 13 of FIG. 3, overcoming 21, both the action of the spring 11 and that of the spring 21, until the plate 17 is moved a distance sufficient to release the extension 5A from the groove 9A. At this point, it is possible to lift the sinker as shown in FlG.. 3 inclining it beyond the illustrated position, and thus withdrawing the sinker in the direction of the arrow f5 of FIG. 3.

In order to assure proper seating of the sinkers within sinker ring 3 as the needle cylinder rotates and carries the sinkers past the access slot a chamfer 13X on the edge of the cam 13A, immediately past access slot 15 as the sinkers rotate, bears against the upper edge of the sinker body and urges dislodged or improperly seated sinkers down into their proper seated position.

Although a preferred embodiment has been illustrated and described hereinabove, it is to be understood that various changes and modifications might be incorporated without department from the spirit and scope of the present invention which is set forth in the following claims.

We claim:

1. A circular knitting machine comprising a needle cylinder, a sinker ring, a plurality of sinkers reciprocably mounted for radial movement on said sinker ring, a spring surrounding the outer end of said sinkers for normally urging the sinkers centripetally, an annular sinker cap supported above the sinker ring, a cam track depending from the sinker cap for engaging butts of said sinkers and urging said sinkers ccntrifugrally according to a prescribed pattern during operation of said machine, said sinker cap having a radially elongated access slot extending vertically therethrough in communication with the inner periphery of the sinker cap and providing open communication with successive individual sinkers therebeneath, said access slot having a width dimension at least equal to the thickness of a sinker, and a yieldable stop means attached to said track terminates on opposite sides of the access slot. 

1. A circular knitting machine comprising a needle cylinder, a sinker ring, a plurality of sinkers reciprocably mounted for radial movement on said sinker ring, a spring surrounding the outer end of said sinkers for normally urging the sinkers centripetally, an annular sinker cap supported above the sinker ring, a cam track depending from the sinker cap for engaging butts of said sinkers and urging said sinkers centrifugrally according to a prescribed pattern during operation of said machine, said sinker cap having a radially elongated access slot extending vertically therethrough in communication with the inner periphery of the sinker cap and providing open communication with successive individual sinkers therebeneath, said access slot having a width dimension at least equal to the thickness of a sinker, and a yieldable stop means attached to said sinker cap and normally biased inwardly across the outer limit of the slot to retain a sinker beneath the slot yet leaving a substantial portion of the slot uncovered so that when the yieldable stop means is moved radially outwardly, passage of a sinker through the slot is permitted.
 2. A structure according to claim 1 wherein said cam track terminates on opposite sides of the access slot. 